Friction-primer for blasting



Patented Mar. 6,1888" jx/wza N PETERS. Pnowmmm ner. wmin n n'jg;

(No Model.)

- A; F. ANDREWS.

FRICTION PRIMER FOR BLASTING.

. NITED STATES PATENT OFFICE.

ALBERT F. ANDREWS, OF AVON, CONNECTICUT.

FRICTION-PRIMER FOR BLASTING.

SPECIFICATION forming part of Letters Patent No. 379,147, dated March 6, 1888.

(No model.)

.To all whom it may concern:

Be it known that l, ALBERT F. ANDREWS, a citizen of the United States, residing at Avon, in the county of Hartford and State of Connecticut, have invented new and useful Improvements in Devices for Exploding Blasts, of which the following is a specification.

My invention relates to devices for exploding blasts, and the purpose is to provide an extremely simple and perfectly safe frictional primer for this purpose which may be used in any kind of blast, which is free from liability of premature explosion or accidental ignition, may be kept for an indefinite period without deterioration, and produced ready for use at a comparatively low cost. 7

The invention consists in the several novel features of construction and new combinations of parts hereinafter fully set forth, and definitely pointed out in the claims.

In theaccompanying drawings, Figure l is a sectional view of a blast-opening with the charge tamped in and the exploder in place ready for firing. Fig. 2 is a longitudinal section and transverse section of the tube of the exploder, showing the manner of constructing the same, the transverse section being shown below the longitudinal view. Fig. 3 is a vertical section, enlarged, of the lower portion of the exploder shown in Fig. 1.

In the said drawings, the reference-numeral 1 designates the exploder-tube, which may be constructed of wood, paper, or any other suitable material. For economy, however, I prefer to form the tube of wood, in which case it may be either square or round, a groove, 2, being cut in one side and partly filled subsequently by a strip, 3, inserted in said groove and glued or otherwise fastened.

The exploder-tube 1 may be of any suitable length; but I prefer to manufacture it about four feet long, one or more additional sections being jointed thereto, if required, when .it is used.

At the lower end is formed an enlarged chamber, 4, containing an explosive material, 5. In the construction shown in Figs. 2 and 3 I form this chamber by simply enlarging the diameter of the longitudinal passage 2. In this enlarged chamber 4 a wire, 6, is coiled within the mass 5 of the explosive material or fulminate, which is of any suitable kind capale of ignition by friction-such, for example, as that employed in the manufacture of parlor-matches.

Below the chambered end of the staff of the exploder the blast-primer 7 may be attached, resting against the friction-primer above it. When the blasting-primer is used in operating with high explosives, the chambered end of the staff is inserted just within the end of the shell 8, which is then closed down upon the staff and the surfaces are waterproofed. The wire 6 is carried up through the slot in the staff, thence out through an opening, 9,just below the end,and looped around the extremity, the loop of the wire lyingin a notch, 10, in the end of the staff. In this way the wire can be operated and the charge fired only by breaking the staff at the point where the wire is looped. The free end of the wire is then attached to a cord or rope, to which a series of such wires may be fastened and all exploded simultaneously.

The coiled end of the wire lying in the paste may be roughened, if desired, though it is not absolutely essential.

It will be understood that the exploder cannot be fired except by breaking the staff at the point where the wire is looped around it, which is done by a twitch upon the wire.

It will be understood that the wire need not be coiledin the paste, though in practice this is preferable. A piece of wire simply embedded therein will give similar results.

The waterproofing is only necessary when the primer is used in damp ground. I may, however, waterproof the complete primer, so that it will not deteriorate in different climates or atmospheric conditions.

What I claim is 1. An exploding device consisting of a staff having a chamber containing an igniting-paste in which a strip of wire is embedded, said wire being extended from the chamber and looped or knotted in a notch or channel formed around the staff, substantially as described.

2. An exploder consisting of a staff having a chamber at one end filled with frictionpastc and a wire embedded within said paste and carried through a channel in the staff to a point near the other extremity, where it is looped or knotted in a' notch or channel formed in the staff, substantiahy as described.

3. An exploder consisting of a rod or staff having a chamber in one end to contain friction-paste,and provided with a channel or bore leading from said chamber to the other end of said staff, and a primer having a shell within the end of which the chambered end of the shaft is inserted, thejoint being rendered Water-proof, the other endof the staff being weakened by a cut or notch in which the wire or cord is knotted, substantially as described.

4. An exploder consisting of a staff having a chamber at one end and a channel leading from said chamber to a notch in the other end of said staff, the chamber being filled With friction-paste, and a wire being embedded therein and carried through the channel to the notch, Where it is looped or tied around the staff, substantially as described.

In testimony whereof I a'ffix my signature in presence of two witnesses.

ALBERT F. ANDREWS. VVi t n esses:

L. F. WEBs'rEn, GEO. A. SAUNDERS. 

